Thanks in great part to help from the users in this forum, i'm progressing. I'm at about 50 wpm now, with accuracy rate averaging just short of 98%. Amphetype has been a great help (https://code.google.com/p/amphetype/) by allowing me to work on accuracy and presenting my progression graphically. I loaded it with a copy of the King James Bible from Gutenberg, edited to remove the verse numbers. That has been providing endless typing fun.

I have been thinking about the differences between typing on a computer or typewriter. On a typewriter, one had to aim for almost perfect accuracy, because correcting mistakes was slow and ugly (unless you had lift-off tape, but that came late in the game).

Younger readers may want to refer to https://en.wikipedia.org/wiki/Typewriter :-)

On a computer, on the other hand, correcting is easy and consequence free. On one hand, this means that we can aim at higher typing speeds and tolerate the occasional error here and there. On the other hand, this can go too far.

I've been noticing in my practice that typing errors often come in clusters. That is, i'm happily typing away, error free, and suddenly i hit the wrong key. Then a quick backspace and even more quickly... another wrong key. Backspace, correct, type a couple of correct keys, then another mistake, correction, mistake, correction, mistake. I think the shock of seeing the screen turn black on Amphetype or red, or whatever way the typing software screams at you: "ERROR! ERROR! AHOOGA! AHOOGA! AHOOGA!"  creates an unstable situation that favors a cascade of errors.

On a typewriter, you had to stop, move the paper, reach for the eraser, etc, then back to the task. I think this natural forced pause had the effect of preventing the error cascade.

I'm going to see if i can train myself to stop for a couple of seconds after correcting a mistake.